Senthilkumar, V. | bioRxiv Science

bioRxiv2025

A searchable database of publications using fluorescent probes and flow cytometry to study antigen-specific B cells

The study of antigen-specific B cells has resulted in important advances in all fields of immunology, the development of experimentally and/or clinically useful antibodies, and as a starting point for rationally designed vaccine antigens. A key innovation allowing for widespread study of antigen-specific B cells was the development of fluorescent antigen probes for use with flow cytometry. Initially these studies were mostly focused upon B cells specific for a variety of model antigens, but over the past decade focus has shifted towards the study of B cells specific for antigens from pathogens such as SARS-CoV-2, HIV, and Influenza virus. Importantly however, these types of approaches have been used for hundreds of different antigens and could be used for thousands more. Unfortunately, studies of B cells specific for an antigen of interest are not easily searchable on current publication databases since these assays are often a small portion of a larger publication. To overcome this, we built a searchable database of studies analyzing antigen-specific B cells by flow cytometry using fluorescent antigen probes that is located at www.immunology.virginia.edu/Taylor/Bcell/Database.php. Using this database, we assessed the number of publications per year revealing rapid growth in the use of this approach in recent years. While much of this rapid growth was focused upon the assessment of B cells specific for SARS-CoV-2, HIV-1, or Influenza virus, studies assessing B cells specific for hundreds of different antigens derived from numerous microbes, animals, plants, or other sources can be found in the database. Combined, the antigen-specific B cell database was built to facilitate identification of studies assessing these cells and for analysis of the field as a whole. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=18 SRC="FIGDIR/small/680531v1_ufig1.gif" ALT="Figure 1"> View larger version (6K): org.highwire.dtl.DTLVardef@f07f5forg.highwire.dtl.DTLVardef@13a3b95org.highwire.dtl.DTLVardef@1dcd79org.highwire.dtl.DTLVardef@9cddaa_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2023

The Toxoplasma subpellicular network is highly interconnected and defines parasite shape for efficient motility and replication

Apicomplexan parasites possess several specialized structures to invade their host cells and replicate successfully. One of these is the inner membrane complex (IMC), a peripheral membrane-cytoskeletal system underneath the plasma membrane. It is composed of a series of flattened, membrane-bound vesicles and a cytoskeletal subpellicular network (SPN) comprised of intermediate filament-like proteins called alveolins. While the alveolin proteins are conserved throughout the Apicomplexa and the broader Alveolata, their precise functions and interactions remain poorly understood. Here, we describe the function of one of these alveolin proteins, TgIMC6. Disruption of IMC6 resulted in striking morphological defects that led to aberrant motility, invasion, and replication. Deletion analyses revealed that the alveolin domain alone is largely sufficient to restore localization and partially sufficient for function. As this highlights the importance of the IMC6 alveolin domain, we implemented unnatural amino acid photoreactive crosslinking to the alveolin domain and identified multiple binding interfaces between IMC6 and two other cytoskeletal proteins - IMC3 and ILP1. To our knowledge, this provides the first direct evidence of protein-protein interactions in the alveolin domain and supports the long-held hypothesis that the alveolin domain is responsible for filament formation. Collectively, our study features the conserved alveolin proteins as critical components that maintain the parasites structural integrity and highlights the alveolin domain as a key mediator of SPN architecture.

microbiology↗